Influence of different chaotropic salts on etched mesoporous silica nanoparticles for the removal of bacteria DNA conveying antibiotic resistance genes from hospital wastewater

The adsorption of bacteria DNA onto mesoporous silica nanoparticles in their original state has been a great challenge due to the high negative charge exhibited by both the DNA and silica surface. The aim of this study is to mediate bacteria DNA onto synthesized mesoporous silica nanoparticles (E-MSN) in combination with different chaotropic salts. E-MSN was synthesized via chemical etching techniques using sodium dodecyl sulfate (SDS) as an etchant. SDS was used to remove unwanted layers and provides a convenient platform for underlining mesopore with different chaotropic salts. Scanning electron microscopy (SEM) coupled with energy-dispersive x-ray spectroscopy (EDX), Fourier-transformed infrared spectroscopy (FTIR), x-ray diffraction spectroscopy (XRD), and point of zero charges (PZC) results showed that synthesized etched mesoporous silica nanoparticles have a crystalline, non-spherical shape and elemental composition of silica at approximately 2 Kev, functional groups that depict silica particles. Molecular characterization of extracted genes showed that Enterococcus faecium harbors tetA, tetM, and ermB in 201bp, 158bp, and 320bp, with the DNA purity ranging from 1.7 to 1.9. DNA adsorption was studied as a function of operating parameters in different solutions of chaotropic salts (sodium chloride (NaCl), 2 M guanidine HCl (CH5N3.HCl), and urea ((NH3)2CO). Among the different chaotropic salts used to compliment the silica nanoparticles, 2 M guanidine HCl exhibited the highest percentage (%) removal efficiency (90%) compared to urea (75%) and sodium chloride (70%) in simulated water and hospital wastewater. Experimental results revealed that the pseudo-second-order kinetic and Sips isotherm is the best fit for the adsorption process. Therefore, mesoporous silica nanoparticles enhanced by different chaotropic salts in this study showed that this material might be promising and economical for the uptake of bacteria DNA conveying antibiotics resistance genes from hospital wastewater. [Display omitted] •The incorporation of chaotropic salts with etched MSN successfully influenced the adsorption of bacteria DNA onto the MSN mesopore.•Synthesis and characterization of etched MSN were investigated.•Removal of bacteria DNA conveying ARGs with etched MSN combined with different chaotropic salts in simulated water and the real hospital effluents recorded high removal efficiencies.•The operating parameters influenced the removal efficiency.•PSO kinetic and Sips i